Current wind power generators generally employ wind turbines and electric motors to generate electricity. These systems are inefficient and expensive to construct and maintain. They are also noisy, intolerant to damage, and relatively difficult to transport and assemble1,2. They can also impose safety and environmental concerns. Unfortunately, a compact, modular, bladeless wind energy system does not exist although some approaches have been proposed. The potential advantages to its development include reduced noise, size, and cost combined with improved portability, efficiency, and cost-effectiveness.
The most common approaches to the design of a bladeless wind generator are based on electro-kinetic phenomena that involve the interaction between an electrostatic and a charged medium in a liquid phase. Electro-kinetic systems require designs that convert air movement to liquid movement and that separate and collect charge for electrical output. Air-liquid and liquid-solid interfaces have to be included in such system, resulting in very low conversion efficiency and high cost of manufacture. For example, Marks, “Charged aerosol generator with uni-electrode source” U.S. Pat. No. 2,406,396, 19773 proposed a vaneless ion wind generator that produces electrical energy directly by using the wind to pump charged aerosols (water droplets) from one electrode to another, with no moving parts. It is obvious that most of the wind's kinetic energy is lost in order to move the charged aerosol from one electrode to another. Daniel Y Kwok, et al, “Electrokinetic microchannel battery by means of electrokinetic and microfluidic phenomena”, Journal of Micromechanics and Microengineering, 13, 964-970, 20034 proposed a microfluidic approach to extract energy from a pressure driven liquid flow in a microchannel.
However, this approach also exhibits low efficiency and high cost because it requires an additional energy-absorbing process to drive the liquid flow in the microchannels where only a weak electric current is induced due to the presence of an electrical double layer in the interface between the liquid and microchannel walls.